1. Field of the Invention
Embodiments of the invention relate to control of an impact mechanism operable by a pressure medium having an element for reversing the axial pressurization of the percussion piston and the return of the medium.
Furthermore, embodiments relate to an impact mechanism for a device for opening and, possibly, for closing a tapping hole in the wall of a metallurgical vessel.
2. Discussion of Background Information
Impact mechanisms for a hammer device axially usable in both directions are known and are part of the prior art.
Advantageously, these impact mechanisms are used in devices for opening and/or closing a tapping hole in a metallurgical vessel.
EP 0930476 A, the disclosure of which is expressly incorporated by reference herein in its entirety, discloses, for example, an impact mechanism having a tubular piston in a hammer device for the above field of use. The same impact energy and impact frequency is thereby essentially applied to the tool in driving and also in retraction during a use.
In order to be able to change the impact frequency and the impact force of the piston of an impact mechanism in both directions, it was recommended according to AT 1397/2011, the disclosure of which is expressly incorporated by reference herein in its entirety, to provide a control recess in the tubular piston and at least two control grooves axially offset in the impact mechanism housing for a reversing of the pressurization of the respective pressure surfaces of the tubular piston and to alternately activate the reversing grooves by a control element. In this manner, it is achieved that the tubular piston executes a different displacement distance or acceleration distance in both impact directions depending on the activation of a reversing groove offset in an axial direction.
Particular challenges for the driving conditions and retracting conditions for tools, in particular of devices in the steel and iron industry, are currently posed by advanced demands for an impact mechanism regarding a controllability of the piston movement.